This study is a continued open label investigation of the safety and toxicity of the agent recombinant methionyl human brain-derived neurotrophic factor. The agent will be given by daily subcutaneous injection for up to 18 months (in the absence of drug related toxicity) to patients who have completed participation in double blind safety/toxicity trials where they have received either subcutaneous or intravenous r-metHuBDNF.